The present invention relates to an apparatus and method of separating multipath and co-channel signals received at an antenna into a strong path signal and a weak path signal and more particularly in one aspect to a bistatic radar signal preprocessor.
As shown in FIG. 1, bistatic radar is radar in which the remote transmitter 2, which includes a transmitting antenna 3, is separated from receiving antennas 5 and 7. A coherent bistatic radar uses two separate signals to compute information about the range and velocity of a target 15: (1) a signal called a direct-path or D-P signal 9 received directly from a transmitter 2, and (2) a version of the transmitted signal called the target-path or T-P signal 13 that has been reflected from some target 15 of interest. Because signals 9 and 13 occupy the same frequency region, conventional bistatic radar systems receive them separately using two directional antennas 5 and 7, respectively, designed to receive signals from a limited region of space. Directional antennas are used since the target path antenna 7 can never accept signals coming from near the transmitter 3. Antennas 5 and 7 feed two separate receivers 17 and 19. The output of the receivers is connected to a two-signal radar processor 21 for extracting target information. The requirement of two directional antennas precludes use on platforms that can support only a single small antenna such as submarines or on a small platform that is required to be highly mobile such as a jeep or man-pack.
It is an object of the present invention to provide multipath and co-channel signal detection using a single receiving antenna.
It is a further object of the present invention to provide a apparatus and a method of performing multipath and co-channel signal detection with a single omnidirectional antenna providing 360 degrees of surveillance.